A welding power source typically comes equipped with a pair of welding cables that form a part of a welding circuit: a work (lead) cable (also sometimes referred to as “ground cable”) that connects the welding power source to a workpiece and an electrode cable that connects the welding power source to an electrode holder holding a welding electrode. During welding, current flows through the electrode cable and an arc is created between the welding electrode and the workpiece. In turn, the work cable provides a current return path to the welding power source.
Work cables are typically attached to a workpiece using work clamps (also sometimes referred to as “ground clamps”). However, present work clamps, including magnetic-type work clamps, pose challenges when used with parts having non-planar surfaces, such as pipes for instance. As one example, in order to make an electrical contact between a work clamp and an outside surface of a pipe, any non-conductive material coating on the outside surface needs to be removed from an area where the clamp is to be connected. As another example, a curvature of a pipe's surfaces can create problems in establishing an effective electrical contact with the pipe's surface. Additionally, a work clamp is often in the way of where a welder needs to work.
Some prior solutions, for instance, provide a brush-type grounding apparatus for grounding an outside surface of a pipe. However, this type of grounding apparatus typically requires a fixture and a rotating part in order to bring a brush in contact with a desired area on the pipe's outside surface.
Further, providing a good electrical contact on an inside surface of a pipe is also challenging. More particularly, an internal diameter of a pipe is typically not perfectly round and a pipe's circumference varies from part to part. This makes it difficult to establish more than a point or line of contact to a part.